<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>Document</title>
	<style>
	body {
		min-width: 600px; /* 2*sub + extra */
	}
	.container {
		padding-left: 210px;
		padding-right: 190px;
	}
	.main {
		float: left;
		width: 100%;
		height: 300px;
		background-color: red;
	}
	.sub {
		position: relative;
		left: -210px;
		float: left;
		width: 200px;
		height: 300px;
		margin-left: -100%;
		background-color: blue;
	}
	.extra {
		position: relative;
		right: -190px;
		float: left;
		width: 180px;
		height: 300px;
		margin-left: -180px;
		background-color: green;
	}

	</style>
</head>
<body>
	<div class="container">
		<div class="main"></div>
		<div class="sub"></div>
		<div class="extra"></div>
	</div>
</body>
</html>
